scholarly journals Using the Mathematical Criterion of Gas Pipeline Failure to Determine the Remaining Operation Life

2021 ◽  
Vol 248 ◽  
pp. 04021
Author(s):  
Minsariya Bayburova ◽  
Zulfiya Ismagilova
Keyword(s):  
Tensile Strength ◽  
Cyclic Loading ◽  
Main Pipeline ◽  
Strength Criteria ◽  
Loading Method ◽  
Underground Pipelines ◽  
Strength Tests ◽  
Pipeline Failure ◽  
Pipeline Route ◽  
Wear Damage

During the years of operation, underground pipelines deteriorate because of aging, wear, damage, and destruction. A comprehensive inspection of the main pipeline revealed various defects on a certain pipeline route section. To identify the remaining operation life of the pipeline, a number of hydraulic tensile strength tests were performed using the cyclic loading method. The authors propose to calculate the minimum allowable wall thickness capable of withstanding the maximum internal pressure, as an alternative to cyclic hydraulic tests. The strength calculations were performed using the well-known mathematical strength criteria proposed by K.V. Zakharov and I.I. Goldenblatt and V.A. Kopnov.

Study of Bismuth Telluride Crystal Strength

2019 ◽  
pp. 1-8
Author(s):  
A. A. Gorbatovskiy
Keyword(s):  
Tensile Strength ◽  
Bismuth Telluride ◽  
Elasticity Modulus ◽  
Testing Machine ◽  
Bend Testing ◽  
Instron Testing Machine ◽  
Measurement Results ◽  
Strength Tests ◽  
Semiconductor Properties

The article presents results of strength tests of bismuth telluride prismatic samples obtained by growing crystals. These crystals have semiconductor properties and are used in the heat machines, the run-ability of which largely depends on the strength of crystals. Data available in the literature are significantly different from each other. It has been shown that, the most consistent strength tests results are obtained in case of bend testing. The measurement results of the elasticity modulus and tensile strength are given. For tests, an INSTRON testing machine with maximum direct stress of the 1000 H was used.

scholarly journals The effect of liquid nitrogen cooling on coal cracking and mechanical properties

2018 ◽  
Vol 36 (6) ◽  
pp. 1609-1628 ◽  
Author(s):  
Chengzheng Cai ◽  
Feng Gao ◽  
Yugui Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Acoustic Emission ◽  
Liquid Nitrogen ◽  
Wave Velocity ◽  
Count Rate ◽  
Initial State ◽  
Nitrogen Injection ◽  
Strength Tests ◽  
Liquid Nitrogen Cooling

Liquid nitrogen is a type of super-cryogenic fluid, which can cause the reservoir temperature to decrease significantly and thereby induce formation rock damage and cracking when it is injected into the wellbore as fracturing fluid. An experimental set-up was designed to monitor the acoustic emission signals of coal during its contact with cryogenic liquid nitrogen. Ultrasonic and tensile strength tests were then performed to investigate the effect of liquid nitrogen cooling on coal cracking and the changes in mechanical properties thereof. The results showed that acoustic emission phenomena occurred immediately as the coal sample came into contact with liquid nitrogen. This indicated that evident damage and cracking were induced by liquid nitrogen cooling. During liquid nitrogen injection, the ring-down count rate was high, and the cumulative ring-down counts also increased rapidly. Both the ring-down count rate and the cumulative ring-down counts during liquid nitrogen injection were much greater than those in the post-injection period. Liquid nitrogen cooling caused the micro-fissures inside the coal to expand, leading to a decrease in wave velocity and the deterioration in mechanical strength. The wave velocity, which was measured as soon as the sample was removed from the liquid nitrogen (i.e. the wave velocity was recorded in the cooling state), decreased by 14.46% on average. As the cryogenic samples recovered to room temperature, this value increased to 18.69%. In tensile strength tests, the tensile strengths of samples in cooling and cool-treated states were (on average) 17.39 and 31.43% less than those in initial state. These indicated that both during the cooling and heating processes, damage and cracking were generated within these coal samples, resulting in the acoustic emission phenomenon as well as the decrease in wave velocity and tensile strength.

scholarly journals Assessment of the mechanical properties of glass ionomer cements for orthodontic cementation

2012 ◽  
Vol 17 (6) ◽  
pp. 154-159 ◽  
Author(s):  
Marcel M. Farret ◽  
Eduardo Martinelli de Lima ◽  
Eduardo Gonçalves Mota ◽  
Hugo Mitsuo S. Oshima ◽  
Gabriela Maguilnik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Resin Modified Glass Ionomer ◽  
Strength Tests ◽  
Diametral Tensile Strength

OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.

scholarly journals Relations between indirect tensile and flexural strengths for dry and plastic concretes

2013 ◽  
Vol 6 (6) ◽  
pp. 854-874 ◽  
Author(s):  
J. T. Balbo
Keyword(s):  
Tensile Strength ◽  
Concrete Slab ◽  
Plane Stress State ◽  
Concrete Mixtures ◽  
Technological Control ◽  
Strength Tests ◽  
Indirect Tensile ◽  
Actual Strength ◽  
Basic Concepts ◽  
Set Up

Indirect tensile strength is not usually used for concrete mixtures proportioning and its technological control; flexural strength tests under third point loads arrangement are the pattern for such goals. Indeed, neither of such tests have the capability to set up the actual strength of a concrete slab since its response is under plane stress state. A critical review of the basic concepts on both kinds of tests allows foreseeing its limitations as well as how to overcome such shortcomings. At last correlations between the two kinds of tensile strength are presented considering dry and plastic concretes typically applied on paving, corroborating to former results achieved for plastic concretes.

scholarly journals An Experimental Study on a Composite Bonding Structure for Steel Bridge Deck Pavements

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaoguang Zheng ◽  
Qi Ren ◽  
Huan Xiong ◽  
Xiaoming Song
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Epoxy Resin ◽  
Bonding Strength ◽  
Bridge Deck ◽  
Steel Bridge ◽  
Shear Tests ◽  
Bonding Structure ◽  
Asphalt Overlay ◽  
Strength Tests

As one of the major contributors to the early failures of steel bridge deck pavements, the bonding between steel and asphalt overlay has long been a troublesome issue. In this paper, a novel composite bonding structure was introduced consisting of epoxy resin micaceous iron oxide (EMIO) primer, solvent-free epoxy resin waterproof layer, and ethylene-vinyl acetate (EVA) hot melt pellets. A series of strength tests were performed to study its mechanical properties, including pull-off strength tests, dumbbell tensile tests, lap shear tests, direct tension tests, and 45°-inclined shear tests. The results suggested that the bonding structure exhibited fair bonding strength, tensile strength, and shear strength. Anisotropic behaviour was also observed at high temperatures. For epoxy resin waterproof layer, the loss of bonding strength, tensile strength, and shear strength at 60°C was 70%, 35%, and 39%, respectively. Subsequent pavement performance-oriented tests included five-point bending tests and accelerated wheel tracking tests. The impacts of bonding on fatigue resistance and rutting propagation were studied. It was found that the proposed bonding structure could provide a durable and well-bonded interface and was thus beneficial to prolong the fatigue lives of asphalt overlay. The choice of bonding materials was found irrelevant to the ultimate rutting depth of pavements. But the bonding combination of epoxy resin waterproof and EVA pellets could delay the early-stage rutting propagation.

Tensile Strength Tests in Epoxy Composites with High Incorporation of Malva Fibers

2016 ◽  
pp. 271-277
Author(s):  
Ygor Macabú De Moraes ◽  
Carolina Gomes Dias Ribeiro ◽  
Frederico Muylaert Margem ◽  
Sergio Neves Monteiro ◽  
Jean Igor Margem
Keyword(s):  
Tensile Strength ◽  
Epoxy Composites ◽  
Strength Tests ◽  
High Incorporation

Assessment of post-heat behavior of cement mortar incorporating silica fume and granulated blast-furnace slag

2020 ◽  
Vol 11 (2) ◽  
pp. 221-246
Author(s):  
Ghasem Pachideh ◽  
Majid Gholhaki
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Blast Furnace Slag ◽  
Strength Test ◽  
Content Type ◽  
Granulated Blast Furnace Slag ◽  
Cement Mortars ◽  
Strength Tests ◽  
Pozzolanic Materials ◽  
Furnace Slag

Purpose With respect to the studies conducted so far and lack of researches on the post-heat behavior of cement mortars containing pozzolanic materials, the purpose of this paper is to investigate the post-heat mechanical characteristics (i.e. compressive, tensile and flexural strength) of cement mortars containing granulated blast-furnace slag (GBFS) and silica fume (SF). In doing so, selected temperatures include 25, 100, 250, 500, 700 and 9000c. Last, the X-ray diffraction test was conducted to study the microstructure of mixtures and subsequently, the results were presented as power-one mathematical relations. Design/methodology/approach Totally, 378 specimens were built to conduct flexural, compressive and tensile strength tests. Accordingly, these specimens include cubic and prismatic specimens with dimensions of 5 × 5 × 5 cm and 16 × 4 × 4 cm, respectively, to conduct compressive and flexural strength tests together with briquette specimen used for tensile strength test in which cement was replaced by 7, 14 and 21 per cent of SF and GBFS. To study the effect of temperature, the specimens were heated. In this respect, they were heated with a rate of 5°C/min and exposed to temperatures of 25 (ordinary temperature), 100, 250, 500, 700 and 900°C. Findings On the basis of the results, the most profound effect of using GBFS and SF, respectively, takes place in low (up to 250°C) and high (500°C and greater degrees) temperatures. Quantitatively, the compressive, tensile and flexural strengths were enhanced by 73 and 180 per cent, 45 and 100 per cent, 106 and 112 per cent, respectively, in low and high temperatures. In addition, as the temperature elevates, the particles of specimens containing SF and GBFS shrink less in size compared to the reference specimen. Originality/value The specimens were cured according to ASTMC192 after 28 days placement in the water basin. First, in compliance with what has been specified by the mix design, the mortar, including pozzolanic materials and superplasticizer, was prepared and then, the sampling procedure was conducted on cubic specimens with dimension of 5 × 5 × 5 mm for compressive strength test, prismatic specimens with dimensions of 16 × 4 × 4 mm for flexural strength test and last, briquette specimens were provided to conduct tensile strength tests (for each temperature and every test, three specimens were built).

Effect of Organo-Shell Materials on Compatibility of the Hydrotalcite Flame Retardant in Ethylene Vinyl Acetate

2019 ◽  
Vol 19 (11) ◽  
pp. 7476-7486
Author(s):  
Jinze Du ◽  
Hongyan Zeng ◽  
Enguo Zhou ◽  
Bo Feng ◽  
Chaorong Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Strength ◽  
Vinyl Acetate ◽  
Md Simulation ◽  
Ethylene Vinyl Acetate ◽  
Flame Retardance ◽  
Strength Tests ◽  
Intrinsic Correlation

The microcapsule nanoparticles were prepared by in-situ copolymerization of hydrotalcites (MAH) with the polymer (MF, PF, PS and PU) monomers, respectively, where the MF-wrapped MAH (MAH@MF) had the best monodispersity. The composites of the microcapsules and EVA were prepared by incorporating the microcapsule nanoparticles into ethylene vinyl acetate (EVA), respectively. To further understand the intrinsic correlation between microcapsule fillers and EVA matrix, molecular dynamics (MD) simulation was introduced to qualitatively analyze the contribution of microcapsule fillers on improving compatibility and mechanical properties of the EVA matrix. The compatibility of microcapsule nanoparticles with EVA matrix were detected in sequence through SEM, DSC and tensile strength tests. And the combustion, thermal behavior and flame retardance were also characterized by TG analyses as well as LOI and UL-94 level. As a result, the MAH@MF filler had the best performances in improving the flame retardancy and mechanical properties among the microcapsule fillers, attributed to high compatibility of the MAH@MF and EVA matrix, which made uniform distribution of the MAH@MF filler due to the reciprocity of triazine functional ring with vinyl acetate linkages.

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